Evaluating the effects of duloxetine on prophylaxis of oxaliplatin-induced peripheral neuropathy in patients with gastrointestinal cancer: A randomized double-blind placebo controlled clinical trial

Background Oxaliplatin is a key drug in treatment of gastrointestinal (GI) cancer. Peripheral neuropathy (PN) is a troublesome and dose-dependent adverse effect of oxaliplatin. It can occur in two distinct forms: acute and chronic. Its incidence is estimated about 65-98%, of which 22% of cases need to stop chemotherapy. In some cases, PN has a long-lasting effect on patient's quality of life (QOL). Therefore, this study was done to evaluate efficacy of duloxetine on prevention of oxaliplatin- induced peripheral neuropathy (OIPN) in patients with GI cancer. Methodology In this randomized and double -blind clinical trial study conducted in a tertiary teaching hospital, eligible patients were divided into two groups. Treatment group received duloxetine the day before initiation of chemotherapy regimen at a dose of 30 mg/day for one week and then, the dose was titrated up to 60 mg/day until 12 weeks. For placebo group, one placebo capsule was prescribed daily for one week followed by 2 capsules daily until 12 weeks. In each of chemotherapy courses, PN was assessed using national cancer institute-common terminology criteria for adverse effects (NCI-CTCAE v4.03). Also, chemotherapy -related QOL at the baseline and 12 weeks was assessed by functional assessment of cancer treatment gynecologic oncology group - neurotoxicity (FACT/GOG-NTX). Results Forty patients were randomly assigned to treatment and placebo groups which were similar to each other in terms of chemotherapy regimen, type, and stage of cancer. Analysis of results obtained from the NCI-CTCAE (v4.03) showed that duloxetine could prevent worsening of paresthesia more than placebo ( P = 0.025) and patients in duloxetine group experienced less peripheral sensory neuropathy ( P = 0.001) than placebo group. Analysis of results obtained from the FACT/GOG-NTX demonstrated a significant worsening of tingling and discomfort in hands ( P = 0.002, 0.001, respectively) and feet ( P = 0.017, 0.019, respectively) in placebo group compared to duloxetine group. Also, patients experienced more cold temperature -induced pain in extremities ( P = 0.001) in placebo group compared to duloxetine group. On the other hand, duloxetine could not improve QOL ( P = 0.06) and had not significant effects on trouble feeling the shape of small objects in hand ( P = 0.420) or trouble buttoning buttons ( P = 0.086). The P-value < 0.05 was considered to be statistically significant.